SPDL1 and glioblastoma: Furthermore, the prognosis of patients with decreasing sPD-L1 in the course of bevacizumab-based therapy did not differ from those where sPD-L1 increased between baseline and the second measurement in both the GBM (p = 0.77) and WHO grade II–III sub-cohorts (p = 0.9) (Supplementary Fig. 2D/E).